1. Field of the Invention
This invention relates to a totally new concept in the fastening of planar objects together and, simply, in the insertion of a rivet into a planar member. This invention is directed to new rivets which can be employed as fastening means, either to fasten two planar members together or to be inserted into a planar member and to serve as an anchor for another material. This invention is concerned with an automatic rivet insertion and extraction apparatus. The insertion-extraction apparatus of the present invention can be in combination with a tool including a power shaft such as an apparatus which supplies rotary motion on the order of an electric drill or the rivet insertion-extraction device can be in the form of a separate unit which can be inserted into the chuck of a standard electric drill and operated by the virtue of the power generated by such drill. The invention is also concerned with automatic means for going from one function to another simply in response to the extent of depression of the trigger. In short, the present invention represents a radical departure from practices heretofore and thus this specification discloses an entirely different concept in the mechanics and operations of rivet insertion-extraction procedures, all as will appear from the more complete disclosure below.
2. Discussion of the Prior Art
In the insertion of a rivet through two juxtaposed planar members it has been the practice to form a hole through the juxtaposed planar members by the use of, for example, an electric drill. A standard drill bit capable of cutting the material of the planar members is employed. After the hole has been inserted the rivet is inserted into a gun. The rivet stem is inserted in this gun leaving exposed a collar member through which a portion of the stem passes which is secured to a flange. The flange is juxtaposed against a facing planar member whereby the collar of the rivet is inserted through the planar members. The stem is then withdrawn by the device holding the same which exerts pressure against the flange while pulling the stem. Ultimately, the collar which is made of a material deformable by the stem collapses over the aperture formed in the first operation so that the collapsed portion of the collar is generally parallel to the flange. Continued pulling action against the stem coupled with pressure in the opposite direction against the flange causes the stem to separate from the collar with a noise. As a result of this operation there is formed a generally flanged member interiorly of the planar members which overlies the inner planar members as the flange of the rivet overlies the facing planar workpiece.
Obviously, there are three steps required in this operation. In the first step a hole is drilled through the planar members to be secured. In the second step a rivet is inserted into a pop rivet gun. The third step involves the placement of the rivet through the aperture formed by the first operation and the following stem withdrawal procedure. Where many riveting operations are desired this takes a considerable period of time for there is much lost motion when one proceeds from the drilling operation to the stem extraction operation.
It, therefore, became desirable to provide an apparatus which would insert the rivet into a hole form and extract the stem of the rivet coterminously therewith whereby there was not required any additional apparatus. It also became desirable to provide an apparatus which would accomplish the hole making and rivet insertion operation and, when desired, the rivet stem extraction operation. Such an object is provided by the present invention.
The presently available rivets are made with a generally conically shaped head portion which can readily be deformed upon extraction with the usual rivet stem extractor. Unfortunately, unless these rivets are made of a highly durable material they cannot be employed as self-cutting rivets in the sense that the hole within which the collar of the rivet lies is formed by revolution of the head of the rivet. It became desirable to provide a rivet which would cut its own hole through a planar member which rivet could be used with a device which would coterminously cut the hole, dispose the rivet in the proper place and extract the rivet stem. Accordingly, it is an object of the present invention to provide a rivet which is capable of cutting its own way through a planar workpiece so as to facilitate the disposition of the rivet collar through the hole so made and behind workpieces whereby upon extraction of the stem of the rivet parallelly positioned workpieces can be secured together. More especially, it became desirable to provide a rivet which would function with the rivet insertion tool of the type desired.
It further became desirable to provide a rivet tool of the type outlined above which had part and parcel therewith an electric motor which would operate a power shaft to facilitate the revolution of a rivet disposed in a chuck thereof which rivet was of the type desired whereby the rivet could cut its own way through at least one planar workpiece whereby to form the hole therein which device would coterminously following the rivet insertion operation extract the rivet stem. Still, moreover, it became desirable to provide such an apparatus of the type outlined above which did not require its own power shaft but could be operated by the use of power generated from a standard electric drill. It became desirable to provide an attachment for an electric drill or similarly chuck equipped instrument whereby the instrument would provide rotary motion for necessary revolution of a rivet disposed in the accessory to facilitate the insertion of the rivet into a planar member which accessory is provided with means for rivet stem extraction.
In certain operations the insertion of a rivet presents problems due to the physical characteristics of the workpiece. Thus, in many instances the rotary power generated by standard available electric drills or the like is not adequate to form a hole in a planar workpiece which can accommodate the rivet. Because of such problems it further became desirable to provide a rivet insertion tool which in addition to having rotary motion of the type possessed by standard electric drills had a reciprocal action to impart a hammering action whereby there would be provided both a longitudinal and rotary force. Such a device is one which would be characterized as having a high impact of the magnitude generated by impact wrenches and the like of known assembly.
Consistent with the above it became further desirable to provide an apparatus on the nature of an electric drill which would be provided with means for automatically moving from one work function, e.g., a drilling function, a hammering function or the like to another function automatically, e.g., an electric drill type apparatus which would proceed from one work function to another work function in response to the setting of electrical switches and/or the position of an on/off trigger. Moreover, it became desirable to provide such an apparatus which is additionally improved by means for automatically closing the chuck of the electric drill type apparatus about a cylindrical member inserted in the mouth thereof. For instance, it became desirable to provide an apparatus which would automatically close the chuck aperture about a drill bit or rivet, commence rotary action to permit insertion of the drill bit to permit cutting of the drill bit or rivet head into a planar member, would automatically undergo an extraction apparatus as in the extraction of a rivet stem and would automatically go into a reverse phase to reverse these operations to an original starting position whereby another drill bit or rivet could be inserted therein to commence a second similar operation.